Which Dinosaur Was the Deadliest?

VO: Noah Baum
WRITTEN BY: Nathan Sharp
They walked the Earth millions of years ago, as gigantic beasts the like of which we can only imagine today. Not all of the dinosaurs were carnivorous predators, but these colossal creatures were definitely very dangerous! So, which dinosaur was the biggest, baddest and most feared? Was the T-Rex really 'King of the Lizards'? Was Spinosaurus the true top dog? Or was there another dinosaur to defeat everything else?

Which Dinosaur Was the Deadliest?

Debating which dinosaur was the deadliest is kind of like asking which living mammal is the most dangerous. While there are definite contenders, there are also plenty of variables. Imperious creatures like lions and grizzly bears immediately spring to mind, but the criteria is so nebulous, and the environments and ecosystems so different, that it’s near impossible to definitively state that one is more dangerous than other.

What we do know, quite obviously, is that carnivorous creatures are more dangerous than their plant-eating, herbivore counterparts. (Although, if a diplodocus stands on you, it doesn’t really matter if it eats meat or not – it’s dangerous!) Other factors like a dinosaur’s agility, size, strength, and the force of its bite are also important – and any creature scoring a solid combination of all four could surely be considered the ‘deadliest’. But, ticking just some of the boxes doesn’t necessarily mean a dinosaur should be feared. The brontosaurus, for example, was a massive and strong creature, but it was slow and led a herbivorous lifestyle, so it was relatively gentle.

That said, a dinosaur didn’t need to be large to be an effective hunter. Take the Utahraptor, which was a relatively small creature, but it certainly packed a punch. The largest reached nineteen feet in length and weighed up to 1,000 pounds. But, despite its comparatively small size, it could successfully hunt dinosaurs much larger than itself – thanks to its massive claws, which were up to nine inches in length. Ouch!

The Velociraptor was another small but efficient killer. Unlike their pop-cultural stand-ins, the Velociraptor was only a tiny thing, measuring up to seven feet long and just one and a half feet high, and weighing up to thirty pounds. On average, it was the size of a hefty chicken, or a stout swan. But the stats shouldn’t fool you. Like in the films, the Velociraptor was an exceptionally quick creature, armed with large, pronounced claws, perfect for attacking and gripping their victims. One especially likely – if pretty gruesome – theory posits that the raptor jumped onto the backs of its prey, clamped its massive claws into the flesh, and fed on its victim while it died of rapid blood loss. Stealthy, speedy and ruthless – sounds pretty deadly, right?

Yes, and no. While raptors were definitely dangerous, they couldn’t take down something like a Giganotosaurus, or any other similarly-sized creature. Many of the deadliest dinosaurs were large, imposing creatures that towered over their probably pretty frightened food sources. The Mapusaurus measured over 30 feet in length and weighed as much as three tons. The Giganotosaurus, as its name suggests, was even bigger – weighing in at between nine and fifteen tons. Then, there was the Carcharodontosaurus, a Cretaceous Period carnivore that was also one of the largest and heaviest dinosaurs to have ever lived. It could reach lengths of up to 44 feet and could weigh as much as sixteen-and-a-half tons. Get in the way of one of those, and you were almost definitely a goner!

With incredible size also came incredible power. The Carcharodontosaurus had a five-foot skull stocked with eight-inch teeth, allowing it to lift creatures up to 900 pounds in its jaws. The Mapusaurus and Giganotosaurus were menacing hunters too, with some speculation that they may’ve hunted in packs. Mapusaurus could take down creatures even as large as the Argentinosaurus (a gigantic animal not surprisingly found in modern-day South America), which is estimated to have weighed up to 100 tons. The Giganotosaurus, meanwhile, had killer teeth packing up to twelve scything serrations per millimetre. Its jaw was also well-adapted for faster biting, just to make it even more difficult to escape them.

But these particular dino breeds rarely get the headlines, and rarely feature on the posters for blockbuster movies. And, there’s probably good reason for that… Because, the Tyrannosaurs were staggeringly dangerous. While the cinema science is often dicey at best, Steven Spielberg at least had that right!

The Tyrannosaurus Rex was one of the largest dinosaurs to have ever existed, with the largest fossilized example (lovingly nicknamed Sue) measuring forty feet in length and twelve feet in height. It is estimated that it weighed as much as fifteen tons, with a six-to-eight ton average, which also makes it one of the largest and heaviest dinosaurs ever. And more than any of the predators mentioned previously, its balance between size, strength and power was pretty formidable. It’s bite was more destructive than anything else its size, with estimates on its exact strength ranging from a 7,000 to a 50,000 pound-force – either of which is strong enough for it to snap apart bones and dine on the marrow within.

Clearly, it could easily kill other dinosaurs. But, the T-Rex was also a bit of a bully. Evidence suggests that it wasn’t above scavenging for food and would often steal carcasses from other dinosaurs. So, while it was more than capable of catching its own meals, it was also clued up enough to let others do the hard work.
An efficient beast, but was it truly the deadliest? Because the Tyrannosaurs were not without their shortcomings. Namely, they weren’t especially quick. Though the suggestions that even a human could outpace them aren’t widely accepted. And there were some unexpected foes, that the T-Rex seemed to have trouble with. The herbivorous (and relatively mild-mannered) Triceratops, for example, may have been a particularly daunting challenge. Fossil records show tooth marks in the remains of a Triceratops’ horn, indicating that it could survive an attack… It’s an exclusive, and incredibly fortunate, club to be in, but clearly the Tyrannosaurus wasn’t always unstoppable.

All of which means that there have emerged many major challengers to the T-rex’s crown as top dino-dog; not least the Spinosaurus, which some see as the true king of the dinosaurs. It’s around the same size as the T-Rex, if slightly longer, and posted a similar weight, if slightly heavier. Crucially, the Spinosaurus fed on both land and marine animals, with a recent isotope analysis suggesting that it sourced meals from within shallow water (sometimes even preying on other dinosaurs while they scoured the waters for food). All in, this was a very versatile hunter, in direct competition with both crocodilians and terrestrial theropods like the Carcharodontosaurus. As a ferocious all-rounder, few were finer than this guy!

Unfortunately for us, but perhaps fortunately for them, the Spinosaurus and Tyrannosaurus didn’t live anywhere near each other – neither geographically or chronologically. So, we don’t have fossil evidence of what a face-off between them would really look like, or anything to prove whether that scene in “Jurassic Park III” is anywhere close to accurate. The Tyrannosaurus lived in today’s North America about 66 million years ago; The Spinosaurus stalked its prey in what’s now the Sahara Desert in North Africa, more than 93 million years ago. Thanks to the planet’s shifting climates, the Spinosaurus was well dead before the T-Rex even existed.

Clearly, deciding on the deadliest dinosaur is no mean feat, but the Tyrannosaurus and the Spinosaurus are the most likely contenders. They shared similar heights, weights, and builds, and they were both incredibly powerful creatures that could eat and kill pretty much anything they came up against. While Tyrannosaurus had the most powerful bite, the Spinosaurus indiscriminately hunted both aquatic and land-based creatures. Plus, there's that smidge of a suggestion that the Tyrannosaurs might have been bested by the humble Triceratops. Perhaps T-rex's apparent weaknesses combine to create a lesser foe?

Either way, if history had ever pitched those two together, it would’ve been the fight of all fights. Throw a Giganotosaurus or Carcharodontosaurus in there for good measure, and you have yourself a prehistoric battle royale to beat all others!